1. Technical Field
This invention relates to the field of hollow tubular projectiles which are launched at supersonic velocities in full caliber sizes from a gun. The objective of this invention is to provide a simple discarding mechanism which will impart spin and seal the propellant gases behind the base of a full caliber hollow tubular projectile that is traveling through the barrel of a weapon system. Upon exiting the barrel, the device separates from the projectile and the projectile continues to fly in a stable mode to target without the usual affixed rotating band required in launching conventional full bore projectiles.
As stated above, tubular projectiles are normally launched at supersonic velocities to achieve the desired flight performance and terminal effects at the target. Full caliber tubular projectiles have been launched with consistent success from guns with the normally affixed rotating bands to impart spin to the projectile The projection of the band from the body surface produces undesirable high drag at the supersonic flight conditions. This drag degrade the flight performance of the projectile. Since a tubular projectile is normally designed to fly in a low drag mode, the rotating band drag can be and usually is significant. There is no known prior art for such a simple device described herein that can provide obturation of gases and impart spin to a full caliber tubular projectile.
2. Prior Art
Numerous design efforts have been used to reduce total drag on projectiles and thereby increase their impact force.
Conventional ammunition projectiles such as used in small caliber and large caliber weapons typically comprise a solid mass with a rounded nose or ogive portion, a generally cylindrical body and an aft or tail portion terminating abruptly in a flat surface normal to the longitudinal center axis of the cylindrical body. Since such projectiles used in weaponry usually leave the gun tube or barrel at supersonic velocity, a relatively blunt nose produces very high drag force and the familiar parabolic shock wave. The blunt tail section results in considerable turbulence aft of the projectile which translates into further drag force from conversion of energy from the projectile to the surrounding mass of air.
To overcome some of the above stated problems, U.S. Pat. No. 4,301,736, entitled "Low Drag Tubular Projectile" was issued to Flatau and Huerta on Nov. 24, 1981. This invention discloses, as shown here at FIGS. 1 through 3, a hollow tubular projectile 20 having about thirty percent less mass than conventional ammunition projectiles and considerably less drag, as a result of precise aerodynamic design details.
In this invention, a hollow center passage through the projectile is found such as to form a tubular shape of circular form 22 and symmetrical about a center longitudinal axis 21 as shown at FIG. 1.
In FIG. 3, the force to launch the projectile 20 is applied to the projectile by use of a unitary force transmitting member which acts as an obturator 24 into which boattail surface 25 may be tightly nestled whereby element 24 transmits forward propulsion force through disc 26 to the projectile 20 being launched.
In addition, in launching a full size or full caliber tubular projectile 20, a rotating band 23 of soft metal, as seen at FIGS. 2 and 3, is generally affixed to the projectile or is made an integral part 23 of the body to the projectile 20 in order for the rifled weapons barrel to impart spin to the projectile 20 to permit the projectile 20 to fly in a stable mode. Such a permanently attached conventional rotating band 23 increases the overall drag of the projectile 20 in flight, hence reducing overall flight performance because of the high rate of deceleration and high drag profile.
Many devices have been utilized for launching tubular projectiles without rotating bands. In the prior art such devices are referred to as sabots. Sabots are used quite successfully in launching sub-calibered tubular projectiles from gun barrels. Such arrangement usually impose size limitations of the projectile body diameter and such a system can not launch full caliber tubular projectiles. There have been described, in the prior art very complicated devices that may launch full bore tubular projectiles from a gun. But, to date, it is not known that any simple device or mechanism sans complicated mating mechanisms, such as, pins, keyways, threading, sequential functioning of components to produce the desired action of the driving mechanism, etc., exists.